Well drilling bit



May'ZZ, 1951 w. F. coMs-rocK WELL DRILLING BIT Filed sept. 1e, 1949 2 Sheets-Sheet l .M M R mm um ma fw May 22, 1951 w. F. coms-rock 2,553,701

WELL DRILLING BIT Filed Sept. 16, 1949 2 Sheets-Sheet 2 mg.. 1-Tab- INVENToR.l v

Wn. man FC5/1S rac/f BY lq 7' TORNEI/S vlsziatentexi Vay 22,

UNITED STATES WELL DRILLIN'G BIT Willard F. Comstock, Charleston, W. Va. Application September 16, 1949, Serial No. 116,167

(Cla VZ55-61) y3 Claims.

p -1 My invention relates to a drilling bit for oil Wells, and the like.

A-primary object of my invention is to provide a weil drilling bit which will drill rapidly through the various formations generally encountered in vthe earths crust, without excessive wear.

A further object is to provide a bit having means to introduce a constant stream of water 'under pressure to the bottom of the hole during the drilling, so that the drill cuttings or 'sand pumpings will be flushed upwardly to the top of the lhole.

A further object is to provide a bit comprising a plurality of separate sections, any number of which may be employed for forming a bit having fthe desired length.

A further object is to provide a removable and replaceable cap or nose for a well drilling bit, said Ynose being either of the moulded Carborun'dum type, or the diamond tipped and studded type.

Adrill-ing bit which is highly simplified, compact,

extremely strong and durable, and relatively in- "expensive to make.

Other objects and advantages of my invention will be apparent during the course of the followiing description.

In the accompanying drawings, forming a part of this application, and in which like numerals are'e'mployed to designate like parts throughout the same,

Figure 1 is a side elevation of a well drilling bit embodying my invention, part in section,

AFigure 2 is a central vertical longitudinal sec= tion through theA same,

Figure Slis a plan View of the bit,

VFigure 4 is a horizontal transverse section taken on line 4-4 of Figure Y1, n

Figure 5 is a similar section taken on line 5 5 of Figure 1,

Figure 6 is a similar section taken on line 6-6 of Figure 1, and,

Figure 7 is a similar section taken on line 'I-'I 'of Figure 1.

In the drawings, where for the purpose of illustration is shown a preferred embodiment of my invention, the numeral I0 designates an elongated straight cylindrical tubular spindle, arranged vertically, and having its top and bottom ends externally screw threaded as shown at II and I2. The top screw threaded end II is adapted-to be screwed into the bottom of a lowermost section of well tubing I3, additional sections of which are arranged above the section I3 and driven into the ground as the drilling proceeds, as is 'well known. y

The bottom screw threaded end I2 has inu'ntrd upon it a lower nose carrying section yor head I4, having a solid central body "portion I5, provided in its vertical side with a plurality of large vertical recesses or water courses I6, which are arcuate in horizontal cross section, and which form a plurality of circumferentiall'y edili-fdisv` tantly spaced vertical ribs I'I. The ribs I'I of the head lli converge downwardly as shown so that the periphery of the head I4, as defined by the ribs il is conically tapered downwardly. The head I@ includes flat horizontal top andy bottom vends i3 and I9, and is provided in its top end with a central vertical screw threaded opening 2t, receiving the bottom screw threaded end I2 of the spindle therein. In its bottom I9, .thehead Id has a central screw threaded opening 2I, for a purpose to be described. In the bottom of the screw threaded opening 20, the Ahead I4 has central vertical recess or bore 22, the bottom of which terminates above the top end ofthe screw threaded opening 2 I, and the Central main body v-portion I5 is provided in its side and above the bottom end I9 with a plurality 'of circumferen; tially spaced passages or ports 23, which are radially arranged and which converge upwardly for communication with the central'bore 2'2. 4The bottom or discharge ends of the ports 2,3 termine ate vbetween and slightly r inwardly of the pel- -ripheral edges of the Iribs I'I, Figure 2.

Secured to the bottom of the head I4 is ya pointed drill cap or nose 2G, which is conically tapered downwardly, and which has a hat top `25 for engagement against the bottom I9. [The cap 2E carries a central upstanding screw threaded stud 26, for engagement within the` screw threaded opening 2i, and thecap is'provided in its conical side with a plurality of longitudinal ydownwardly converging cutting groovesor lands '21, which extend from the bottom `or point28 of the cap Yto its top 25 as shown. `These cutting grooves 2l are generally longitudinally straight, but may be spirally arranged, if desired. H The nose or cap 2d may be formed vfrom a suitable moulded abrasive material, such as moulded Ca-rbo'rundum, and it may be provided witha diamond point or tip, and diamond studded `in its side if desired. Y Y

-Icontemplate providing a plurality of 'noses or caps with my bit. The diamond tipped and studded nose or cap may be employed when cutascyoi ting through extremely hard formations in the ground, while the moulded abrasive noses mall be used to cut through softer formations.

The ribs I'I of the head I4 are provided in their outer faces with straight longitudinal dovetailed grooves 23, extending throughout the entire lengths of the ribs and through the top and bottom of the head I4. Removably mounted within these dove-tailed grooves 29 are straight elongated cutters 30 of Carborundum, or the like. These cutters 33 are tapered radially outwardly as shown, and project radially beyond the outer faces of the ribs Il. The ribs Il and cutters 30 are so arranged about the head I4 that the bottoms of the ribs and cutters are spaced circumferentially between the cutting grooves 21 of the nose or cap 24, and adjacent to the conically tapered peripheral portions 3l of the nose or cap. This arrangement places the grooves 2'I of the nose or cap in communication with the recesses or water courses It of the head i4, so that the drill cuttings or sand pumpings may be ushed upwardly through the grooves 27 and into and through water courses I6. The top 25 of the nose 24 engages the bottom ends of the cutters 3U to retain them within the dove-tailed grooves 29. The screw threads upon the stud 26 and bottom end I2 are formed so that when the drilling bit rotates during drilling, the head I4 and nose or cap 24 will be tightened. Removably mounted upon the lower head I4 in contacting superposed relation are a plurality of intermediate body sections or segments 32, having central solid main body portions 33, provided with central vertical aligned cylindrical bores 3d, receiving the tubular spindle I0 therethrough, in assembly. The sections or segments 32 have a close sliding fit upon the tubular spindle, and any number of these segments may be employed, with a spindle of the proper length, to produce a drilling bit of the necessary length. While I have shown four of the segments 32, it is to be understood that I do not wish to restrict the invention to this number, and any desired number of sections may be employed, as previously stated. The adjacent contacting faces of the segments 32 are connected` and held against relative rotation by means of dowel pins 35, and a similar dowel pin 33 connects the lowermost segment or section 32 with the head I 4, and holds these elements against relative rotation. The segments 32 are provided in their sides with equi-distantly circumferentially spaced large vertical recessed passages or water courses 31, forming equi-distantly spaced radial ribs 38, provided in their outer vertical faces 38 with vertical lon- 'gitudinal dove-tailed grooves 39, extending for the entire vertical lengths of the ribs, and removably receiving elongated straight vertical cutter sections 4B, of Carborundum, or the like. These cutter sections 43 carried by the ribs of the segments 32 engage the sides of the well bore above the tapered lower end of the bit and maintain the bore of the well at the desired diameter. The recessed passages 3'I are of the same size as the tops of the recesses I6, and register with each other in assembly and with the tops of the recesses I5, to form continuous vertical channels or water courses about the side of the bit, for conducting upwardly water ladened with the sand or cuttings formed at the bottom of the hole by the bit. Likewise, the ribs 38 of the segments 32 register in assembly and register with the tops of the ribs I'I. The ribs 38 are of the same width as the ribs I'I, and the cutter sections 4U have 4 the same shapes and widths as the cutters 3D carried by the head I4. The cutter sections 43 of the adjacent segments 32 have their adjacent ends contacting, and the lowermost cutter sections 40, carried by the lowermost section or segment 32 contact the tops of the cutters 3i). The cutter sections 43 are thus held against downward longitudinal movement in the grooves 39, and cannot move radially because of the dovetailed shape of the grooves.

Above the intermediate body sections or segments 32, I provide one or more dummy sections or segments 4I, having the same general shape as the sections or segments 32, and not being provided with cutter sections, like the sections 46. The dummy section 4I has a bore 42, receiving the spindle I3 and is provided with recessed passages 43 and radial ribs 44 for registration with therecessed passages 37 and ribs 38 in assembly. The outer diameter of the dummy section 4I, as measured about the periphery dened by the ribs 44 is larger than the outside diameter of the sections 32, so that the lower ends of the ribs 44 of the dummy section will extend over the tops of the uppermost cutter sections 40 to hold all of the cutter sections 43 against upward movement, Figure 4. The dummy section 4I is connected with the uppermost section or segment 32 by a dowel pin 45, which prevents relative rotation between the elements. In addition to securing the cutter sections 4B in place, the dummy section 4I gives additional length to the bit, and additional dummy sections may be employed where necessary to provide a longer bit.

Above the dummy section 4I, I provide one or more upper body or guide sections 4S, doweled to the dummy section 4I by a lower dowel 4l, and having a central bore 43, receiving spindle Iii. The guide section 4S has a central solid body portion 49, provided in its side with vertical recessed passages 5G for registration with the recessed passages 43 and 37, and forming with such rocesses the continuous vertical water courses about the bit for the upward passage of water and drill cuttings or sand pumpings. The guide section 45 has radial ribs 5I which project radially outwardly for the same distance as the cutter sections 4G for defining the same outside diameter which the cutter sections 4l] dene. These ribs 5I serve to guide the bit within the hole which has been produced by the cutters 36 and cutter sections 40.

Arranged above and upon the guide section 45 and doweled thereto by means of a dowel pin 52 is a separate body cap or top 53, having a bore 54 receiving the spindle I0, and a solid upwardly conically tapered body portion 55 provided in its side with circumferentially spaced, recessed passages 56 which extend through its top and bottom 5T and 58. The passages or recesses 5t have their bottoms in registration with the recesses 50 to form therewith and with the recesses 43 and 3l' the continuous vertical channels or Water courses extending from the point of the nose 28 upwardly along the bit, to the top thereof, for conducting upwardly the Water ladened with sand or drill cuttings as stated. The top 53 further includes upwardly converging radial ribs 59, the bottoms of which register with and engage the tops of the ribs 5I. The top 5'! forms a lateral shoulder for the bottom end of the tubing section I3.

The operation of the well drilling bit is as follows: Y Y

The tubing including the bottom section I3 is S rotated by conventional machinery including a rotary table supported on the ground at the top or head of the well, and the tubular spindle l is rotated by the tubing and rotates the bit. The head l and nose 24 must and will rotate With the spindle i9. The dowel pins 3E, 35, 45, 4l, and 52 cause the various sections 32, 4l, @e and 53 to rotate as a unit with the spindle it, and the various superposed sections cannot partake of relative rotation because oi"- the dov/el pins, and cannot move axially, because they are held down by the bottom of the tubing section i3, which engages the top end l. The various separate superposed sections are thus tightly clamped together upon the head ifi for forming a continuous unitary bit.

As the bit rotates, the Carborundum or diamond tipped and studded nose 24 penetrates the ground and starts the cutting action. This cutting is continued by the radially projecting inclined cutters 33 of the head i4. The vertical cutter sections til iinish the cut above the head ill as the bit descends, and serve to produce a straight, clean, and uniform cut. lf the cutters 3&3 wear before the cutter' sections de, and this is usually the case, the cutter sections iii will iinish the cut to the proper diameter. The ribs 5i oi the guide section 46 serve to guide or pilot the top end of the bit, which is sometimes quite long, depending upon how many of the sections 32, 4I, and 46 are employed.

The nose 2li is readily removable and replaceable, so that when wear occurs a new nose may be readily applied. Further, when cutting through extremely hard substances, the diamond tipped and studded nose will be employed, rather than the Carborundum nose, which is adequate to cut through softer substances.

All of the cutter sections lili, as well as the cutters Sil are readily removable and replaceable when worn, by removing the dummy section li and the sections above it, and sliding the cutter sections e@ vertically out of their respective dovetailed grooves. The cutters 36 are likewise removable longitudinally from their grooves 29, when the sections 36 are rst removed from the spindle.

During the drilling, water under very high pres sure is continuously forced downwardly through the tubing sections from the top of the well and through the bottom section i3 and the bore of the tubular spindle I6. This water passes out through the ports 23 and flushes about the head I4 and nose 24. Upon leaving the ports 23 the water ows into the water courses It of the head I4 and into the cutting grooves 2l of the nose 24. The Water will ush away the sand or cuttings formed by the drilling operation, and convey the cuttings or sand pumpings upwardly through the wide water courses formed by the recesses 31, 43, 5t, and 5E. The water and cuttings will eventually pass to the, top of the hole.

It is to be understood that the form of my invention, herewith shown and described is to be taken as a preferred example of the same, and that various changes in shape, size and arrangement of parts may be resorted to, without departing from the spirit of the invention or the scope of the subioined claims.

Having thus described my invention, I claim:

1` A well drill bit assembly comprising an elongated tubular spindle having screw thread formations one at each end thereof, a head including a central portion having a centrally disposed recess provided at one end of said head with screw threads receiving one end of said spindle and radially projecting ribs disposed at substantially equal angular intervals around said central portions, said ribs being inclined inwardly from said one to the other end of said head and the central portion of said head having radially disposed passages therein extending from said recess to the exterior of said central portion between adjacent ribs, a conicalY drill nose secured at its larger end to said head at said other end of the latter, body sections mounted on said spindle and each including a central portion provided coaxially with a spindle receiving bore and having ribs projecting radially therefrom at substantially the same angular intervals as the ribs on said head and to substantially the same extent as the ribs on said head at said one end of the latter, said head and. said body sections having flat and substantially parallel end surfaces, means interconnecting said. body sections and said head maintaining corresponding ribs of said head and said body sections*V in alignment longitudinally of the bit, said body sections together constituting a stack mountedv on said spindle with one end in contact with said. one end of said head, a dummy section mountedv on said spindle at the other end of said stack.

of body sections and comprising a body of sub-A stantially the same diameter as the central por-- tions of said body sections having a central bore receiving said spindle, a guide section mounted, on said spindle at the end of Said dummy sectionA remote from said stack of body sections and in cluding a central portion provided with a central' bore receiving said spindle and ribs projecting: radially from said central portion at angular in-4 tervals and substantially to the same radial ex-4 tent as the ribs on said body sections, the ribs. on said head and said body sections being notched. at their outer ends to provide undercut grooves extending longitudinally of said bit, and elon gated cutter sections of hard material seated onef in each of said grooves.

2. A well drill bit assembly comprising an elon gated tubular spindle having screw thread forma-` tions one at each end thereof, a head including a central portion having a centrally disposed; recess provided at one end of said head with screw threads receiving one end of said spindle and radially projecting ribs disposed at substantially equal angular intervals around said central portion, said ribs being inclined inwardly from said one to the other end of said head and the central portion of said head having radially disposed passages therein extending from said recess to the exterior of said central portion between adjacent ribs, a, conical drill nose secured at its larger end to said head at said other end of the latter, body sections mounted on said spindle and each including a central portion provided coaxially with a spindle receiving bore and having ribs projecting radially therefrom at substantially the same angular intervals as the ribs on said head and to substantially the same extent as the ribs on said head at said one end of the latter, said head and said body sections having ilat and substantially parallel end surfaces, means interconnecting said body sections and said head maintaining corresponding ribs of said head and said body sections in alignment longitudinally of the bit, said body sections together constituting a stack mounted on said spindle with one end in contact with said one end of said head,`a dummy section mounted on said spindle at the other end of said stack of body sections and comprising a body of substantially the same diameter as the central portions of said body sectionshaving a central bore receiving said spindle, a guide section mounted on said spindle at the end of said dummy section remote from said stack of body sections and including a. central portion provided with a central bore receiving said spindle and ribs projecting radially from said central portion at angular intervals and substantially to the same radial extent as the ribs on said body sections, the ribs on said head and said body sections being notched at their outer ends to provide undercut grooves extending longitudinally of said bit, and elongated cutter sections o hard material seated one in each of said grooves, the spaces on said head and said body sections between adjacent ribs being arcuately concave to provide Water channels extending longitudinally of said bit between adjacent ribs of said head and body sections.

3. A Well drill bit assembly comprising an elongated tubular spindle having screw thread formations one at each end thereof, a head including a central portion having a centrally disposed recess provided at one end of said head With screw threads receiving one end of said spindle and radially projecting ribs disp-osed at substantially equal angular intervals around said central portion, said ribs being inclined in- Wardly from said one to the other end of said head and the central portion of said head having radially disposed passages therein extending from said recess to the exterior of said central portion between adjacent ribs, a conical drill nose secured at its larger end to said head at said other end of the latter, body sections mounted an said spindle and each including a central portion provided coaXially with a spindle receiving bore and having ribs projecting radially therefrom at substantially the same angular intervals as the ribs on said head and to substantially the same extent as the ribs on said head at said one end of the latter, said head and said body sections having flat and substantially parallel end surfaces, means interconnecting said body sections and said head maintaining corresponding ribs of said head and said body sections in alignment longitudinally of the bit, said body sections together constituting a stack mounted on said spindle with one end in contact with said one end of said head, a dummy section mounted on said spindle at the other end of said stack. of body sections and comprising a body of substantially the same diameter as the central portions of said body sections having a central bore receiving said spindle, a guide section mounted on said spindle at the end of said dummy section remote from said stack of body sections and including a central portion provided with a central bore receiving said spindle and ribs projecting radially from said central portion at angular intervals and substantially to the same radial extent as the ribs on said body sections, the ribs on said head and said body sections being notched at their outer ends to provide undercut grooves extending longitudinally or" said bit, and elongated cutter sections of hard material seated one in each of said grooves, said dummy section having ribs at angular intervals therearound projecting radially a distance somewhat less than the radial projection of the ribs on said body sections and overlying the adjacent ends of said cutter sections to maintain said cutter sections in said grooves.

WILLARD F. COMSTOCK.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,019,679 McColgan Mar. 5, 1912 1,547,459 Staiord et al July 28, 1925 1,701,427 Shields Feb. 5, 1929 2,088,770 Skinner Aug. 3, 1937 

